Calulating Balistic Coeficent

[Johnch]

I have http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi to use calulate it with start velosity and another velosity at a known distance

But I would swear at one time I had bookmarked a calulator to use drop between 2 distances and start velosity ( may have needed more info )

Anyone know of a way to calulate it without a second velosity ?

John

[redneckdan]

http://www.uslink.com/~tom1/calcbc/calcbc.htm

[Johnch]

Thanks
I will try that

But unless they have changed the calulator , OR my memory is failing me
I remembered a different set up

John

[montana_charlie]

Anyone know of a way to calulate it without a second velosity ?Some software uses characteristics of the bullet, combined with the muzzle velocuty to produce a ballistic coefficient value.

However, it's difficult know IF those bullet characteristics used apply exactly to your bullet.

Using a method that relies on two velocities, taken at different ranges from a single fired bullet, provides results that ONLY apply exactly to that bullet.

Therefore, a result derived from two velocities is a 'calculated' ballistic coefficient...while a number deduced from bullet characteristics and a single velocity is merely an 'estimate'.

CM

[redneckdan]

I've found that calculator to be pretty close. Definitely close enough to get on paper at extended range and work from there to verify your 'clicks' for various distances.

[Harter66]

I've used the same 1 redneck dan suggests , then coupled that with the "shooter lite" app for my phone (since I live on the darned thing and never get to use the comp.at home anyway). Shooter has proven very accurate if you get all the right numbers in , I let it use the GPS last week instead of using standard averages and the poi was within an inch up and down of on a 1.5 inch group. It gives you the options for drift and up/down hold also.